Implement SequenceTypeExtractor

idea/idea-jvm/src/com/intellij/debugger/streams/kotlin/psi/sequence/SequenceTypeExtractor.kt

@@ -2,18 +2,52 @@
 package com.intellij.debugger.streams.kotlin.psi.sequence
 
 import com.intellij.debugger.streams.kotlin.psi.CallTypeExtractor
+import com.intellij.debugger.streams.kotlin.psi.KotlinPsiUtil
+import com.intellij.debugger.streams.kotlin.trace.dsl.KotlinTypes
+import com.intellij.debugger.streams.trace.impl.handler.type.ClassTypeImpl
 import com.intellij.debugger.streams.trace.impl.handler.type.GenericType
+import com.intellij.openapi.diagnostic.Logger
 import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.typeUtil.supertypes
 
 /**
  * @author Vitaliy.Bibaev
  */
 class SequenceTypeExtractor : CallTypeExtractor.Base() {
+  private companion object {
+    val LOG = Logger.getInstance(SequenceTypeExtractor::class.java)
+  }
+
   override fun extractItemsType(type: KotlinType?): GenericType {
-    TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    if (type == null) return KotlinTypes.NULLABLE_ANY
+
+    return tryToFindElementType(type) ?: defaultType(type)
   }
 
   override fun getResultType(type: KotlinType): GenericType {
-    TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    val typeName = KotlinPsiUtil.getTypeWithoutTypeParameters(type)
+    return KotlinTypes.primitiveTypeByName(typeName)
+        ?: KotlinTypes.primitiveArrayByName(typeName)
+        ?: ClassTypeImpl(typeName)
+  }
+
+  private fun tryToFindElementType(type: KotlinType): GenericType? {
+    val typeName = KotlinPsiUtil.getTypeWithoutTypeParameters(type)
+    if (typeName == "kotlin.collections.Sequence") {
+      if (type.arguments.isEmpty()) return KotlinTypes.NULLABLE_ANY
+      val itemsType = type.arguments.single().type
+      if (itemsType.isMarkedNullable) return KotlinTypes.NULLABLE_ANY
+      val primitiveType = KotlinTypes.primitiveTypeByName(KotlinPsiUtil.getTypeWithoutTypeParameters(itemsType))
+      return primitiveType ?: KotlinTypes.ANY
+    }
+
+    return type.supertypes().asSequence()
+        .map(this::tryToFindElementType)
+        .firstOrNull()
+  }
+
+  private fun defaultType(type: KotlinType): GenericType {
+    LOG.warn("Could not find type of items for type ${KotlinPsiUtil.getTypeName(type)}")
+    return if (type.isMarkedNullable) KotlinTypes.NULLABLE_ANY else KotlinTypes.ANY
   }
 }